Space heater



May 26, 1942.

R B. EVANS ET AL SPACE HEATER Filed Sept. 30, 1938 5 Sheets-Sheet l May 26, 1942. R. EVANS Er A.. 2,284,138

SPACE HEATER Filed sept. 3o, 1938 Ssheets-sheet 2 1N VENTO/es. Foie/"Z ,3. 271/4275,-

ATTORNEY May 26, 942.

R. B. EVANS ITAL SPACE HEATER Filed Sept. 50, 1938 v 5 Sheets-Sheell 3 5. MWF@ A E if, f 1 if Y E f3; .if 0? 5. mx um M V a1 Mii May 26, .1942. R. B. EvANs ErAL SPACE HEATER Filed Sept. ,50, 1958 5 Sheets-Sheet 4 May 26, 1942- R. B. EVANS ETAL l v 2,284,138

SPACE HEATER Filed sept. so, 1938 5 sheen-'sheet 5 A TTOR Patented May 26, 1942 SPACE HEATER Robert B. Evans, GrossePolnte, and Eugene F. Farrell, Detroit, Mich., yassignors to Evans Products Company, Detroit, Mich., a corporation of Delaware Application September 30, 1938, Serial No. 232,502

36 Claims.

This invention relates to air circulating unit heaters, and particularly to room or space heaters of the forced air circulating, portable, self-contained unit, cabinet type, burning oil, gas, or the like, and preferably arranged for a blower-forced discharge of high temperature (up to about 250 F.) air directly into the room close above its oor but not immediately striking the floor or, selectively, for operation by natural upward thermal circulation.

Objects of this invention are, in general, to provide improved and simplified features and arrangements for an air circulating heater including a high temperature combustion unit of this portable unit or self-contained cabinet type which preferably has blower-forced downward air circulation therethrough; to provide a heater of this type constructed to give a particularly eilicient and safe forced distribution of the high temperature air in a 10W level, Wide, thin stream directly from the heater cabinet into and throughout the room or rooms to be heated, particularly by discharging this flat stream of high temperature air across and close to but slightly above the room oor so as not to over-heat or injure the floor or its covering; and to provide a simple arrangement of the blower, shutter unit, and other\parts for suchl a heater whereby it can be operated safely and without danger of overheating the blower motors, the'shlxgters, the cabinet, and other parts with blower-forced down flow of the air being heated.

Other objects of this invention are to provide a space heater of this type having improved means for lling of its fuel or oil tank which is positioned inside of its cabinet; to provide connections whereby an outside fuel tank may be used if desired; to provide accessible controls mounted on the front of the cabinet of such a unitspace heater, and particularly to provide such accessible controls upon the front of the removable shell type cabinet; and to provide a forced air circulating space heater in which the blower unit not only forces heated air into the room but also provides a cooling current of air over the oil tank, the shutter unit, and other partsto prevent overheating thereof.

Other objects of this invention are to provide a unit space heaterl of this type formed almost lentirely of sheet metal which can be cheaply manufactured and assembled by modern production line methods; to provide such a heater, composed of removable and replaceable units, which can be readily and easily serviced in the eld;

and to provide a heater o f this type in'which assembly unit which includes suitable frame` members carrying practically all parts, i. e. the blower unit, the oil tank, the ccmbustion unit, the top damper unit and substantially all of the several operating parts; and to provide, in a space heater having such a chassis, a rigidly connected or one-piece open bottom outer shell cabinet member having suitable openings and grilles'therein, which open bottom cabinet shell is removably and slidably fitted down over the complete upright chassis unit and yet is rigidly braced by this chassis unit.

Other objects of this invention are to provide in such a forced air circulating unit cabinet heater an arrangement of the blower unit, the oil tank, the combustion and heating unit, and the other operating units in an outer cabinet shell to give an eicient heat transfer and air circulation, a cooled oil tank, and a comparatively cool or non-burning outer cabinet shell, and particularly to make possible such a blower forced air circulating heater of very large heating and air oW capacity but which has all of 'its parts completely enclosed in a compact, shallow depth, limited height cabinet of the so-called low boy type having an attractive appearance and space conserving proportions for home use; and to provide an eicient andattractive type of grille for the air openings of'such an air circulating heater. t

Other objects of this invention are to provide, for use in a space heater or ythe like, a cheap blower unit of the duo-tandem fan type which is quite compact and readily removable, this unit comprising a compact housing containing two small electric motors arranged side by side and each having a fan at each end; to provide a simple vibration and noise absorbing mounting for a blower unit of this type; to provide a heater unit of this type in which the blower may also be employed for summer ventilation or air circulation when heat is not used; to provide'a'single unitary damper or closure means comprising a plurality of shutters selectively permitting or preinvention will become apparent from the follow\ ing specification, the drawings relating thereto, and from the claims hereinafter set forth.

In the drawings. in which like numerals are used to designate like parts in the several views throughout:

Fig. 1 is a perspective view of the iront and side of the complete space heater unit with portions broken away to show the interior construction; 1

Fig. 2 is a front elevation of the front of the heater unit with the front of the shell cut away to show the interior and with the top grille omitted;

Fig. 3 is a transverse vertical section taken on the line 3-3 of Fig. 2;

Fig. 4 is a horizontal section taken on the line 4 4 of Fig. 2; y

` Fig. 5 is a transverse vertical section taken on the line 5-5 of Fig. 2;

Fig. 6 shows a part of a similar heater having a modified form of air intake for the blower unit. This gure is otherwise similar to the upper lefthand portion of Fig. 2;

Fig. 'I is a perspective view showing the details of the base or the lower portion of the chassis assembly unit;

Fig. 8 is a plan view showing the oil iiller spout unit with its cover removed;

Fig. 9 is an elevational view showing the oil ller spout unit with its cover;

y Fig. 10 is a plan view showing shutter unit and its thermostatic control;

Fig. 11 is an elevational view showing details of the shutter unit and its thermostatic control together with a schematic showing of the Wiring diagram or motor control circuit and switches;

Fig. 12 is a perspective view showing the details of the upper removable grille;

Fig. 13 is a perspective view showing details of the upper removable mounting for the oil tank;

Fig. 14 is an end view showing a modified form of blower unit;

Fig. 15 is a front elevation of this modified form of blower unit;

Fig. 16 is a section taken on the line IB-IG of Fig. 14;

Fig. 17 is an end view showing another modiy fled form of blower unit Fig. 18 is a section taken on the line I8I8 of Fig. 17;

Fig. 19 is a transverse sectional view similar to Fig. 3 showing a modiiled form of linkage for Vmanual operation of the shutter; and

the use of certain aspects and `features of thev present invention is not necessarily limited to this particular type of heater, but may extend to different devices including other types of heaters.

Ventilating or air conditioning apparatus. or the like, all within the purview and scope of the present invention as set forth in the subloined claims.

In unit space heaters of the general type of the present invention. there are a number of rather different but interrelated considerations and conditions which it is necessary or desirable to satisfy by suitable features and compromise arrangements in such heaters. Among them are the highly competitive market for such devices and the consequent necessity for a heater which can be manufactured from a small weight of sheet metal and assembled at low cost in large scale production; the desirability, for similar reasons, for standardized parts production and removable units, giving cheaper and smallervcapacity models by omission or removal of certain units; the necessity for low cost of operation, including low fuelcost, from high efficiency and ease and low cost of repairs and servicing; the requirement. from its widespread use in homes or the like, that the parts oi such unit be formed and arranged to give the unit a large heating and air circulating capacity with a limited cabinet size and an exterior shape or proportions such that the heater cabinet will not take up much iloor a space when positioned against the room wall and details of the l will have an attractive appearance as an article of furniture; the desirability for such a cheap and compact heater to have means, including a cheap. compact blower unit, to give an elcient and safe blower forced circulation of heated air and to have safety features for avoiding the danger of overheating the blower electric motors or other parts by the heated air, eliminating the danger oi burning or overheating the floor from a low level discharge, keeping the outer shell temperature relatively low to prevent burns, and keeping the inside oil .tank and associated parts sufficiently cool.

It is desirable, particularly when the heater is running at a high or full fuel setting, to force the heated air out adjacent the room iioor. The blower-forced circulation of hot air through the heater will, of course. materially increase the air heating capacity of the heater unit over that obtainable by natural or convection type of air circulation. and cause a desirable circulation within the room or space to be heated. The discharge of hot air close to the floor, and' particularly a blower-forced, wide, thin stream of hot air discharged along the door, will prevent cold ioors and stratification of the air, which is one of the objections to a convection circulation space heater or to. a space heater using a blower to force the air upwardly or outl into the room at a high level. The more uniform distribution of warm air throughout the height of the room increases comfort and decreases the amount of heat. and consequently fuel, necessary to maintain a comfort level in the more critical portion of the room, which is close to the iioor.

In connection with the above mentioned danger of burning or injuring by over-heating the room floor or its covering by a direct blower-forced discharge thereon of the high temperature air from a combustion type space heater, it should be noted that a combustion type space heater of the type disclosed herein, when operating at full capacity. may discharge the air from its lower openlow boy type. paratively shallow from front to back so as not to protrude too far into the room. The over-all ing at temperatures as high as or more than 215 F. Air at such temperatures, or even at considerably lower temperatures, will injure the floor or common door coverings such as linoleum. The Underwriters will not permit unit space heaters to raise the oor temperature more than about 90 F. above ordinary room temperatures. Although it has been proposed heretofore to use a blower with a combustion unit type of space heater to force the hot air out the blower end, such proposals are believed impractical since the high temperature air impingesdirectly on the oor and will dangerously over-heat the same.

Therefore. aparticularly important feature oi' the present invention is the provision of a combustion unit space heater in which the air is heated to high temperature and which is constructed so that the blower-forced high temperature air is discharged directly into the room close to but slightly above the oor in a substantially horizontal direction so that it will not strike the floor in any appreciable degree until it has moved out far enough from the heater to become sumciently cooled. It has been found in' connection with a heater of the type disclosed that after the discharged air has moved out about one and onehalf feet from the heater the widening stream does strike the floor to some extent, but its temperature is reduced sufiiciently so that it is quite safe and not injurious to the floor or its covering.

It is believed that the problems arising from these several considerations and conditions, which have not been entirely realized or satisfactorily solved by the space heaters of the prior art, have been advantageously met by the teachings of the present invention.

For a better understanding of the details of the invention, reference may be had to the drawings in which:

Reference numeral I represents the unitary` and removable outer shell lof the cabinet. This shell unit I is formed voi? suitably stamped and connected pieces of sheet metal reinforced and having openings therein for the several grilles hereinafter described. Since the present heater unit is intended to be placed up against a wall for circulating heated air throughout the room or rooms of homes, oices, cottages or the like, it is important that the heater as a whole, and particularly the outer shell, be of desirable size and shape and of pleasing exterior appearance. The heater cabinet illustrated is of the so-called It will be noted that it is comheight is limited by considerations of appearance. It will be apparent that this stamped onepiece outer shell construction lends itself tothe manufacture of the illustrated type of cabinet having all yits corners rounded and suitably enameled and otherwise decorated.

The numeral 2 represents the base or chassis assembly as a whole, as shown in Fig. '7. The base and complete chassis assembly are supported by feet 3 which are one-piece sheet metal stamplngs decoratively embossed, as shown. Angles 4 are Welded or otherwise suitably secured to the feet 3 to form' the front and back rails of the base, and angles 5, similarly secured, form the end rails. Base plate 6 rests in rail channels 4 and one end channel 5, and= is welded or otherwise secured to them and to feet 3 to form Ia rigid base unit. Base plate 6 has a simple elongated or oval opening 'I (as shown in Figs. 4, 5

and 7) and integral tangs or lugs 8 are struck lpg from the metal of the plate around this open- The left-hand end of plate 8, as seen in Fig. 7. rests in and is welded or otherwise suitably se?- cured to angle iron 8 which is similarly secured to the frontend back rails 4.

Feet 3 have bolt holes III on their top portions to receive the outer shell holddown bolts. as later described.

The left-hand portion of the base 2 is open, as shown by I I in Fig. 7. This opening is bridged by a sheet metal member I2 suitably secured to transverse channels 8 and 5.

Upright angle irons I3 are welded to the base 2 by integral turned-over feet I4. Upright angle irons I5 are mounted on the front and back of the blower end of plate 6. Solid partition plate I8 is welded to channel 8 and extends from the base plate 6 to the base lof the blower unit.

An additional partition plate I'I may be welded or otherwise secured to channels lI5 to increase the heat insulation.

As seen. in Figs. 2 and 4, the lower corners of the shell I carry retaining lugs I8 having suitable holes to receive bolts I9, to be received in holes lo in the base feet, to thus removamy secure the shell to the base.

Angle irons 20 and 2| are welded to the front and back of the shell to provide between them a channel to receive the whole length of the front and back edges of partition plate I6 to brace the rather light sheet metal shell I against weave or deformation with respect to the chassis assembly.

The oil burning combustion units are enclosed in upright oval expansion chamber 22, the lower edges of which are secured to plate 6 by screws through its up-turned tangs 8, as best seen in Fig. 5. As shown in Fig. 5, the lower end of chamber 22 is partially closed by a bed plate 23 screwed or otherwise suitably secured to chamber 22 by integral down-turned flanges 24. Bed plate 23 has small circular air intake openings positioned under each burner unit. Each of these openings has integral down-turned lugs 25 about its periphery to support circular plate baffles 26 with these air intake openings.

Burner retaining and partition plate 21 is suitably secured by an integral up-turned ange 28 in the chamber 22. Two circular holes 29 in plate 2l support two conventional pot-type burner units, the details of which are not described here since they may be of any desired type and since they form no part of the present invention. O

'Ihe upper end of the expansion chamber 22 is closed by a top plate 3I having its up-turned flange 32 welded or otherwise sitably secured to chamber 22.

The expansion chamber 22 is surrounded by a spaced shroud or cowl member 33 having door opening 34 and a cut-out portion at 35, as seen in Figs. 1, 2 and 4, to permit the blast of air from the fans of the blower unit to enter shroud 33 and to be confined by it to close proximity to the'hot metal surface of the expansion chamber 22. Shroud 33 is secured on the expansion chamber 22 by suitably welded-on brackets `36.

The expansion chamber 22 has a suitable circular opening 31 for a section of the flue connection 38 which passes through a corresponding circular opening 39 in shroud 33. Flue connection 38 is secured to member 2'2 by an out-turned ange 40. A short section of iiue connection pipe 39a is tightly fitted over the slightly tapered end of section 38 vertical rods 'and has an` outwardly` rolled portion 39h to present a tapered surface which is shoved into and thus tightly tted in circular opening 4I of the cabinet shell I. The conventional fiue pipemay be fitted over the slightly tapered end of 33a. d

Conventional door opening 42 in the expansion chamber22 matches opening 34 in the shroud 33, and there is a corresponding door 43 in the outer shellV I.

Any desired or conventional form of oil supply float chamber and `control valve -for each pot burner are enclosed in a common housing 44 which is suitably mounted on member I2 above the opening II. Door 44a in the end of cabinet I permits access to the valve unit.

The unillustrated rotary valves for regulating the supply of oil to each pot burner may be of any conventional or desired-type, as will be apparent to those skilled in the art, and their details form no part of the present invention.

Each of these valves is suitably connected to rotatable clips 45 on the top of the housing 44 (see Figs. 1, 2 and 4). 'I'hese valves may be individually manually adjusted to regulate the oil ilow to, and hence vthe height of, the'ame in each burner unit by means of any desired linkage. The preferred' linkage comprises the aforesaid clips 45, short vertical rods 46, universal joints of the Hookes type 41, long inclined rods 48, universal joints ofthe Hookes type 49, short 50 (see Fig. 5), and horizontal regulating wheels I carried by brackets 52 and extending to the outside of the cabinet through suitable openings 53 in the cabinet shell. The two Hookes joints 41 and 49 are arranged with their pivots at right angles to each other so that movementsv of the control lwheels 5I give corresponding equal angular movements of clips 45, as is well understood in the art concerning the use of universal joints. The inclined rods 48 pass through suitable closely fitting holes 48a in partition plates I6 and I1. Regulating wheels 5I carry suitable indicia to` indi-cate the valve settings. l

As shown in Figs. 3 and 5, bracket 52 is removably secured to the linner surface of the shell I by screws 52a. -Note that this linkage for manual control of the oil valves is simple and compact and offers no possibilities of gettingout of adjustment. 'The doiwnwardly extending rods 5U, as used in this linkage, permit the use of spaced rotatable controls having vertical axes. Fnremoval of the shell for repairs or the like, the screws' 52a are .removed so that the controls 5I may be. pushed-in to disconnect the valve control linkage from the cabinet shell.

As shown in Figs. 1, 2 and 4, oil supply pipes 54 are provided with suitable or conventional ttings at either end and lead from the valve and iioat chamber housing 44 to each of the burner units 30. A similar oil supply pipe line 55 leads from the oil tank 56 to the housing 44 and has a. T tting 55a'with an end plug 55h intermediate its length to permit the connection of an oil supply pipe from an outside large tank through hole 5 5c in the back of the cabinet shell I to the T fitting 55a in place of its plug 55h. Where such an outside large tank is connected in this fashion, the oil tank 56 may be removed, if desired, and plug 55h used to close off the top of the T fitting 55a.

It is desirable that the oil tank 56 be nnly and yet removably secured on the upright frame or upright portions of the chassis base assembly to facilitate repairs and the like. As shown in Figs. 1, 2 and 4, tank 56A has integral flanges 51 along its upright back edges. Upwardly facing channel 58 extends all the way across partition plate I6 adjacentth top of the oil tank and is suitably and rigidly secured to this plate I6. As shown in Fig. 4 and in detail in Fig. 13, the upper portion of tank 56 is hung on or removably secured to this channel 58 by two spaced pins or buttons 60 which are suitably fixed on the back of tank 56 and are received in open topped slots 59 in the outer flange of channel 53. Note that pins or buttons 60 have enlarged outer ends to engage the inner side of the outer ange of channel 53. As shown in Fig. 2, the lower end of tank 561s removably secured to the yiframe by having the downwardly extending bracket or strap 6I rigidly secured to the lower portion of tank 56 and removably secured to plate I6 by screw' 6Ia which is accessible from under the oil tank 56.

It will be apparent that when the outer shell I is removed, the oil tank 56 can be readily removed by unscrewing screw 6Ia and simply lifting the oil tank out of place. Assembly, which is the reverse of this operation, is equally simple.

Reference numeral 62 represents the indicator member for a conventional iloat type oil lever indicator which is well-known in the art and the details of which are not described herein.

The arrangement for lling the oil tank is shown in Figs. 1, 2, 4 and in detail in Figs. 8 and 9, wherein the removable filler spout unit 63 is shown as having the removable cover fitting into its top and a suitable straining screen 65 mounted in the bottom of the cylindrical portion of unit 63. Unit 63 has the lower end of its cylindrical portion removably and rotatably mounted in the equivalent diameter filler opening of the oil tank 56 and is supported thereon by its outwardly projecting portion above the lower end. Cover 64 is down-turned at one end so that it iits into and closes not only the cylindrical portion of unit 63 but its curved filler spout portion.

Note that as shown in Figs. 1,v 2 and 4 filler spout unit 63 is rotatably mounted to one side of the oil tank and to one side of door 66, which door is suitably pivoted at its top to be-swung open for filling and also for inspection of the oil level indicator 62. 'I'he vpositioning of the rotatable mounting of illler unit 63 at one side of this door opening permits its long illler spout t be readily swung out through the door opening to receive oil poured into it by the user.

'As shown in Figs. 1 and 2, the compact blower unit 61 is removably mounted upon the upper portions of the upright frame members of the chassis base assembly unit in the upper end portion of the housing shell, but is entirely unconnected to and independent of the removable housing shell I.

In the form shown in Figs. 1, 2, etc., the blower unit comprises a four-sided, rectangular housing or box 61 having its otherwise open ends partially closed and stifiened by similar end plates 2,254,138l l a protection against a user getting his fingers into the fan blades.

'I'he motor fan units are removably mounted in the blower housing by the following structure. As shown in Figs. 1 and 2, heavy metal straps I2` are welded to and extend from front to back ofv the top and bottom of the housing 61 to stiilen the same and to carry upright metal straps 13 having integral, turned-over ends 1d which are welded to straps 12. The central portions of straps 19 are curved to conform to and hold the electricv motors. It will be noted that upright straps 13 stiften and serve as braces for box 61. Strap members 15, having their central portions similarly curved to t the electric motors, are removably secured to straps 13 by bolts and nuts 16 to clamp tightlyv/a band of vibration and noise absorbing or insulating material 11 surrounding the small, conventional, electric motors 18 which carry multiple-blade conventional, propeller-type fans 19 upon the armature shaft at each end thereof.

It will be noted that the blower unit in its housing 61 extends substantially from front to back of cabinet shell i and is of a very limited height for a large volume capacity unit. The adjacent side-by-side fans are close to each other and extend substantially from front to back of housing 61 and the cabinet l. Since there are two sets of fans operating in series upon the air streams, the blade pitch of the second or'innermost fans may be made greater and otherwise modified to compensate for the faster-moving air it receives, as is well understood in the art relating to tandem propellers.

This arrangement of two sets of tandem fans side by side may be termed, for the sake of convenience, a duo tandem? arrangement, and it will be apparent that such an arrangement is particularly advantageous in the blower unit for use in a low boy type, cabinet, space heater or in other installations in a compact housing wherein it is important that all space be emciently used and the over-all height of the cabinet or housing is limited. This form of blower unit is cheap to manufacture because small size, and cheap, standard, electric motors and fan blades may be used in lieu of the specialized and more expensive larger motors and fans. In addition, this blower unit makes use of two sets of standard parts which may be used in building smaller, forced-air heaters with one tandem set, or the like.

Blower unit 61 is removably secured to uprights or frame angles 80 which are welded to the sides of housing 61 and are removably bolted to said uprights I with a noise and vibrationl deadening backing 8| between angles l5 and 80.

As shown in Figs. 2, 3, and 11, the top closure damper or shutter unit is removably secured across the top of the frame uprights of the chassis base assembly unit. 'I'his flat, rectangular shutter unit comprises upwardly extending channels 82 having integral, down-turned ends 83 on their webs which are screwed or otherwise remoyably secured to the top of upright frame members l5. A plurality of sheet metal shutters 84, having alternately up-turned and down-turned longitudinal edges to interlock when they are closed to provide a better closure, extend substantially from front to back of the housing shell I between suitable shelves or bracket plates 84a and 84h welded or otherwise secured on the innerback surface and front surface of shell I, respectively, to match the outer edges of the shutter unit. It will be apparent that this unit is simple and compact, occupying little vertical space even when open, which is an advantage whenthe closure is positioned underneath a top grille such as grille H5.

A closure unit occupying considerable heightcould not be positioned under a top grille with! out increasing the over-all height ofthe heater or modifying the design of the expansion chamber or the like. y

As will be apparent to those skilled in this art, other types of closure units which are compact, and occupy little vertical space or heightmay be used within the purview of this invention.

As shown in Figs. 1 and 3, each shutter 8E is bent or crimped along its central portion to provide a recess to carry suitably welded-in pivot rods 86 which are mounted in suitable aligned pivot holes in end channels 82.

As shown in Fig. 3, and, in part, in Figs. 19 and 20, each shutter has a slot 81 extending in from one edgethereof, and one or more of said shutters carry suitable counterweights 81a'. If desired, spring 81h is also connected to pull said shutters open. Suitable pivot rods 88 extend' across each slot 81 and are connected to a bent wire or strip interconnecting-member 89 by its integral bends or loops 90 which enter slots -81 and. extend around each pivot 88, which pivots are held on each shutter by suitably welded-on or up-struck strips 9i. The front shutter is pivotally connected to the over-turned end of a metal wire or rod link 92, the other bent-over end of which is removably sprung into a pivot f hole in the outer end of handle lever 93 which is pivotally mounted on the lower end of strap or bracket 95 carried by and depending from bracket 84h. 'Ihe other end of handle lever 93 extends through a vsuitable opening 96 in the cabinet shell l and carries a removable knob 91 at its outer end.

One of the shutters, preferably the central shutter, has a holding member or cam 98 of metal or suitable brous material xedly secured on its pivot 06 intermediate the ilanges of channel 82 and extending down through an opening 98a in the web of channel 82. Member 98 has a pre-determined, oval, cam shape. Thisshutter has a locking recess 99 at one end thereof.

Bimetallic spring strip l00. is riveted intermediate its ends to the under side of the web of channel 82 and is formed so that each end thereof will move downwardly upon increasing temperature, as is well understood in the art relating to bimetallic spring members. This thermostatic strip |00 carries a suitable projection or bent-up member I0! at its inner end which may engage in and hold rotary locking plate 98.

It will be apparent that the above provides a very simple, fool-proof, and cheap mechanism for holding the interconnected' shutters (which are spring and/or gravity biased towards open position) closed whenthey are closed by the manually operated handle 93-91.' It is, in effect, a spring or snap detent to hold the shutters ciated parts are suitably calibrated and arranged so that member 98 will be released-,permitting the shutters to open-at' a desired pre-determined temperature which will be somewhat in of and just above the blades .'19 of the innermost fan on the front side. These blades 19 extend into and partly through the cowling formed by the flanges B9 and will throw some of the discharged air out in a more or less radial direction (a well-known characteristic of this type of fan). Some'of this air stream will necessarily strike strip and this-airstream will be relatively cool since the fans draw a part, vof their air supply down throughl grille ||`iand a part up around oil tank f56 andpast partitiony I6. This stream of relatively cool air acting as long as the fans are running will keep the simple and small bimetallicstrip |00 sumciently cool so that it will definitely latch-orrhold the biased shutters closed even though the whole upper part of the cabinet and heater unit may be quite hot in normal blower-heating operation.

Thus the temperature responsive element |00 is located in a relatively high velocity stream or is struck by a substantial amount of relatively cool air coming into the air heating passage. It will be apparent to those skilled in this art that various designs or expedients may be used to get this relatively high velocity stream of incoming orl substantially unheated air acting directly on the temperature responsive element. Preferably, as specifically disclosed herein, but not necessarily, the temperatureresponsive elementis quite close to the fans or blower and is located on the discharge side since the velocity is greater there.

Due to the rapid removal of heat from strip |00 by the portion of the relatively cool fan blast which strikes it when the fans are running, and since it will heat up rapidly when the fans stop, it will be apparent that the temperature responsive unit operates between two widely separated temperatures for its holding and its releasing positions so that a small simple unit can directly exert a greater vforce .or have a greater It will be apparent that when the shutters are closed for blower-forced downward air circulation, the blower unit should be running. Otherwise the hot air and heat trapped by the closed shutters-some of which would escape through the blowerv unit-would injure the motors 18 and possibly warp or otherwise injure the shutter unit itself and the enamel and finish of the cabinet unit.

The present, automatically-openable, top closure unit avoids these dangers since, upon reaching this predetermined excess temperature, the inner end of bimetallic spring strip |00 has moved down sulciently to release plate 90 and permit the shutters to open, thus permitting release ofthe entrapped air and heat by normal, upward, gravity or thermal circulation.

If desired, means may be provided in the electric circuit for the blower motors so that, in normal heating operation with the fans running, they may -be initially turned on but will not be energized to start until the temperature of the air inside the spaceheater has been raised to a pre-determined point to thus prevent circulating'cold or unwarmed air throughout the room.

For this purpose, a bimetallic, spring-strip controlled switch is used and, if desired, and as shown in Fig. 11, it may be the other end of the bimetallic spring strip |00 carrying an insulating pad |0|a which, in turn carries contact |02. Another insulating pad |03 carries co-acting contact |04 and is mounted on bracket |05 which is suitably secured on the inside of frame up right or angle l5. Contacts |02 and |04 are in travel (as is required for the latch organization herein) than in the case of a temperature responsive element acting on small temperature diilerences, as is true of most thermostatic regulators. Its operation is, in effect, dependent. upon whether or not the fans are running so that there is a denite combination relationship.

This feature is quite important. It makes possible the use of a cheap, simple temperature responsive unit. It eliminates the necessity for a delicate, sensitive, or accurate temperature responsive system or for relays or the like in order to have suilcient force exerted on the latch to hold it firmly against accidental release and to release it quickly and definitely when' the fans stop. It would be difllcult to design a cheap, simple, and durable temperature responsive holding and releasing system for the top closure without employing this feature. For example, if vthe temperature responsive element were not struck and cooled by an appreciable amount of substantially unheated incoming air, or if it were simply positioned remote from the fan unit, such as at the other end of the shutters, a simple unit of this type would not be possible.

current to the parallel-connected fan motors 10. Contacts |0| and |02 are bridged by a wire |08 having therein a simple, manually operable switch |09, which switch is preferably mounted decorative and protecting grille is removably mounted in a suitable opening in the top of the cabinet shell I. This rectangular grille consists of a retaining rim formed of an open, rectangular, rim plate having its outer edge downturnedl and having both its ixmer and outer edges turned over to stifen it. A corresponding, open, rectangular plate H2, having its edges bent in reverse directions, as shown, is welded or suitably secured to plate to form a channel to receive the ends and sides of the louver unit.

It is desired that the louvers, which run across the width of the grille, be attractive and sturdy, and yet oier small resistance to air flow. Accordingly, they are narrow from side to side, of an appreciably greater depth, and have a streamline cross section to give low resistance to downward air flow and also a small resistance to upward air flow. At the same time, they have an attractive appearance with smooth, rounded, upper surfaces. Although they may be made in any conventional way, the preferred form is shown in detail in Fig. l2, wherein the streamline," louvers ||5 and their connecting members Aunitrises up around the oil tank tocool it and `its valve unit, and in order to'proportion the II4 are integral and `are formed from one large, ai'. piece of sheet metal which -has suitable openings cut therein and then has a rounded or connecting pieces I I4 to hold them in place, as will be apparentI from, an inspection of Fig. 12.

There is an elongated air intake opening II6 opposite the oat chamberl 44. Grille I I'I is secured in this opening. The grille I I I is preferably formed as shown in detail in Fig. l12.

' curved bent made along the centerline of each l louver portion, leaving the horizontal, integral,

Air discharge opening I|8 extends along the j bottom portion of the other end of the cabinet shell and carries grille IIS, the louvers of which may, if desired, provide air deecting vanes or fins which are of suicient width to aid in deecting the blower-forced downward flow of hot air from its downward path into a substantially horizontal path so that this very hoi'l air will not impinge upon and burn the licor-or iloor covering close to the heater..

As illustrated, it may be desirable to have these louvers IIS slightly up-turned to deect this air stream slightly upward from the horizontal,

n as is shown in exaggerated fashion by the louvers and the arrows in Fig. 2. It will, however, be apparent that this feature may be omitted if desired.

Similarly, long narrow opening extends across the bottom portion of the front of the.

heater close above the bottom plate 6 and a grille I2I similar to that described above for opening I|8 is mounted therein, the louvers of .which grille |2I provide air deecting vanes or iins, as described ab'ove.

Preferably, louvers IIS and I2I are formed as shown in detail in Fig. 12

As shown in Fig. 2, upright frameangles I3 carry at their tops plate I22 .which is suitably screwed across the open top of channel I22 which, in turn, is secured to angles I3 and forms the end of the shutter unit. This closure plate I22 is shaped to t the end and curved .corners of the outer shell I so that with the shutter unit closed it prevents any air from arising through the top of the heater during blower heating operation. n

In order `to humidify the air in the room being heated, and as shown in Figs. 1 and 2, a humidifier pan |24 may be removably `mounted by having itsV opposite edges received in slides |25 so that it is positioned under part of the open space beneath the float chamber control valve unit of the oil tank. Thus it will be apparent that some of the air being drawn up through this open space to go up around the oil tank will sweep across the water of thispan |24.

Fig. 6 is generally similar to the structure shown in Fig. 2 except that it shows a modied arrangement for supplying air to the fans in which partition plate 200, which is welded or otherwise suitably secured by its integral ange to the shell I, extends out over and rests on the fan housing 61 to close off airsupply coming from above Vor over the shutter unit. It will be apparent that when the shell I is lifted up off the chassis assembly, member 200 may be lifted .with it from fan housing 6l. In order to reduce the resistance to I'low and to give a portion of the air being supplied to the fans a straight path, an opening 202 is provided in the shell I opposite the intake side of the blower unit and has mounted therein a grille 203, the details of which are interconnected by a single elongated sheet are preferably formed as in Fig. 12. As in Fig.

2, a portion of the air supplied to the blower relative amounts of air coming up from-around the oil tank and coming through the opening 202, there is provided a baille 20| with a bent end Welded or otherwise suitably secured to the shell. The length of member 20| and angle at which it is bent will determine the amount of air coming up from below.

Figs. 14, 15 and 16 disclose a -modii'led and preferred form of blower unit and its mounting, wherein the housing for the complete unit and the shrouds for the two sets of tandem fans are formed fby two symmetrical sheet metal stampings 300 each providing two side-byside and integrally connected semi-cylindrical portions. A piece of comparatively heavy strap iron 30| is received between and extends across these members 300 and has two curved portionsv formed therein to receive the electric motors, which are horizontally clamped therein by two upper clamping members 302 removably secured to member 30| by bolts and nuts 303. Note that the ends of clamps 302 are formed to be spaced and held above strap 30| so that they can be taken up and sprung by the tightening of the bolts to give a resilient clamping action.

The blower unit is entirely supported by carriage or .buggy type springs 304 which absorb noise and vibration. These springs are suitably bolted at 305 to upright' frame angles I5 and to the projecting outer ends of member 300 and to member 30| at 306. Screws 301 hold together the projecting end `flanges of the two housing members 300. Central bolts 308 clamp together the embossed portions 3I0 of the housing member 300 about the strap 30| to secure the central portions of the blower unit.

Figs. 17 and ldisclose a modied form of blower unit which is similar to that of Figs. 14,- 15 and 16 except that the semi-cylindrical housing and fan shroud portions are separate so that they will form standard parts which may be used in building blower units having only one vset of tandem fans. This modiiication also may be desirable when it is found disadvantageous to make too large a stamping. In this form, suitable clamping bolts 308 clamp together-the four semi-cylindricalA members 309 by their overlapping edges or ends 3I0 about the central strap 30|. Figs. 19 and 20 show a modified and preferred formv of the upper shutter unit and controls therefor and.' in addition, show certain details of the shutter unit of Figs. 1` and 3,y as will 'be apparent from the equivalent reference numbe' s.

Fig. 19 illustrates a manner of securing pins 80, which extend across open-ended slots 81, to the shutter 84 by suitable, integral, struck-up straps 9|.

In this preferred embodiment, the shutters 83 metal stamping 3|2 having upwardly extending portions 3I3 extending up into slot V'II and receiving pins 88. .An elongated metal handle rod 3I5 has its inner, bent-over end removably'secured by cotter pin 3I6, or the like,'to the interconnecting member 3I2.

It will be apparent that when the shutters are open the operator can reach down between the open shutters and remove the cotter pin 3I6 which passes through a hole in the-bent-over end of member 3I5 to thus disconnect this handle rod 3I5 and permit its withdrawal so that the outer shell unit, having been disconnected at the other s 4 points, may be freely from --chassis assembly unit. .The outer end of handle v rod 3|! extends through a suitable opening in v openings inplate 23 t0 the'shelland carries a handle knob, substantially as shown in Fig. 3. l l

v Operation The pot-type burners ing 34, and opened door I3, after turning on the oil by control.. used to set the valves in theimit 4l to regulate or turn of!l the oil flow to each burner.

A detailed descriptionofthe operation of the pot-type oil burner units 33 is not given herein asserts u are nghtedmlthe con; l

ventionil fashion through opened door l2,- openmp'nmg Hg,

j heels 3i. Controls 3l arc-'alsoA since it'is well-known in this art.v Airtosupport this combustionis supplied from the space under the bottom plate l, upward through the oval opening 1, around the bale or. regulating plate 2l, and in through the circular air intake the space around the two burner umts 3i). This air then goes in through the plurality of openings in the sides of burner units 30 and picks up'oil or oil vapor so that the flame may burn either at low level from the lower' bame. or at a regulated height from the upper plate.

The products of combustion rise and expand in the yexpansion chamber 22, which extends substantially from top to bottom and through the major part ofthe width and depth of the entire v cabinet shell Iso that it has ample volume to permit expansion and provides a large areafor eilicient heat transfer.

The smoke and flue gases discharge through theilue connection 39, 38a, and the usual stack.

Note that the ilue opening 31 is connected to the back of the expansion chamberbelow its top to cause a swirling of the hot gases, instead of being connected with the less efncient, straight -through passage into the stack.

In heater units in which the blower unit and the "shutter unit are not'included, or in units having the blower, but where it is not turned on, this heater operates by gravity or by natural, upward thermal circulation in which air from adjacent the iloor enters the upwardlyextending all; heating passage through openings |20 and I 8.

Note that no air can enter the air heating passage through the closed bottom plate 6.V

The air heating passage extends from'bottom plate 6 to and through the open'top of the cabinet l between the expansion chamber 22 andthe walls of cabinet shell I. On the left side of the heater (as shown in Fig. 1), this passage is bounded by the partition IG-l'l, which partition meansprevents any of the hot air from getting over into the end chamber which holds the .oil tank, etc.

Shroud 33 extends entirely around and throughout most of the height of the expansion chamber 22 to more closely coniine the upwardly 'flowing air stream to the heating walls of chamout through the open shutters of the top grille III into the room.

Y opening I2lto 'rise andvilow around the float `chamber-control valve unit'll, theoi1 tank 3l, and up'around the fan unit and 'out through the Note'that some of this hazard. Thus the cil tank and the fuel control valves, floatA bowl, etc., are Vpositioned in a chimney havinglarge areav openings at its base and large-area openings at its top for free ilow -to keep-the oil tank, etc.' cool.

This upward flow of cooling air is partly due to' this chimney effector the upward convection current caused by the certain amount of heat Vwhich is transmitted to this end chamber' through lthe partition I3-i'l and the walls o! shell I, and is partly induced by the adjacent and more vigorous Vilow through the upwardly extending air heatingpassage. Some flow of relatively cool air through the blower unit (and past the fan motors to cool them) into the upwardly extending air heating. e will be induced by the main upward ilow of hot air in the air heating 1355881815-v It will be apparent that high temperature air -from the main heating e does not -tlow through the blower unit, which is oiIset or positioned to one side out ofthis main upwardly extending air heating passage to avoid this and the consequent over-heating of its electric motors.

For blower-forced air circulation, the fan motors 18 are turned on by switch I III, and the shutters 34 are closed by pushingr handle 3l of Fig. 1, etc., upwardlyor pushing handle 3l! of Fig. 19 inwardly.

'Ihe lduo-tandem fans discharge a wide stream of 4air (substantially the width .of the cabinet) across the ltop of the cabinet shell.

It win be apparent that the nosed shutter unit, together with plate |22, entirely closes oil the whole upper portion of- -shell I except for the blower discharge. Cut-away -portion 35 in the shroud 33 provides an opening permitting the major portion of the blast of air from the fans to impinge directly on the hot expansion chamber and to enter the space between the shroud and the expansion chamber. This blast is retlected from the other end of the shroud 33 and the other .end wall of the shell vI 'and follows a turbulent and generally downwardly extending path, which is roughly'indicated by the arerows in Fig. 2. It will be seen that this turbulent now will give a high heat exchange efliciency Y tribution ducts, or the like, are used with this portable, unit heater. e

It is also desirable that the hot air be forced into the rooms in a wide, ,thin stream close to and across the floors, so thatheat may rise from this low stream to give a more uniform temperature throughout all portions of the rooms. This low, wide stream avoidsA stratification or heating e air rises through the4 space between the vback ofthe oil tank and partition IO-'-I1 so that all sidesof-theoil tank are cooled to prevent 'exceasiv'e'v'aporization of the oil or other fuel, thus reducing the smell and nre adjacent its bottom or base plate 6. Since, as illustrated, these openings II8 and |20 are narrow and have a relatively small total discharge area,

they will inherently direct the discharged air (by their jet or nozzle action since they are, in ef feet, constricted openings) into a wide thin stream moving out substantially horizontally from the cabinet so that the high temperature.

air will not immediately strike the floor or its covering to injure or dangerously over-heat the same. The small height or the narrowness of these openings or slots II8 and |20 is important in horizontally directing this air discharge. For example, the directional effect would be much less in the case of a circular, square, or similarly shaped discharge opening having the same total area as openings I I8 and I20. In addition, the plurality of horizontal louvers or vanes II9 and |2| extending across each of the long openings I I8 and |20 divides them into a number of even narrower openings or .slots to increase their directional eiect. The Width of the vanes-I I8 and |20 (which, as noted above, may be slightly upturned if desired) also aids in deilecting the downwardly moving stream of high temperature air into a substantially horizontal discharge stream.

During blower-heating operation, the intake air for the fans comes in from two sources. One portion rises up through the left-hand or end chamber (as seen in Fig. 1) through opening IIB and the large opening I I to cool the oil tank, etc., as described above for non-blower operation. Another portion is drawn down through the low resistancelouvers of grille II5, across the closed shutters to cool them, turns, and is drawn into the fans to cool their electric motors. Thus the 'blower unit air intakes are of relatively large area and consequently oier small resistance to the air flow. As noted above, the lower discharge openings. II8 and |20 are relatively small so that the air heating passageways (the spaces between the 9 fan-units of Figs. 14 through 18, inclusive, operate in the same way as described above. A

In the modifiedv form of blower air intake shown in Fig. 6, the second portion oi' this intake air has a low resistance path straight across from opening 202 into the fans.

In the forms of both Fig. 1 and Fig. 6, and during heating with or without blower operation, it will be apparent that part of the intake air is always humidied by sweeping across the water l inremovable pan IH.

If the operator should fail to open the shutters, or if the fans should stop or fail to go o n when the shutters have been closed i'or blowerheating operation, the shutters will be automatically opened to release theentrapped hot air which would otherwise pass by and over-heat the fan motors and injure theshutters or the like.

The shutters are biased towards open position by Weight 81a and spring 8'Ib and are held closed by thermostatic spring |00 engaging the cam plate 98 which moves with the shutters 84. Aty

a pre-determined temperature, spring |00 moves down to permit the shutters to open. The portance and the advantages of positioning this" temperature responsive element in the fan blastof incoming air are discussed above.v

In blower-heating operation, it may be desirable to prevent the blower from circulating nonheated air by delaying its starting, after ithas been turned on by the usual outside switch |I0, until the heater has come up to the proper temperature. As shown in Fig'. 11, thermostatic switch IBI- |02 keeps the blower motor circuit open until a pre-determined temperature in theI `through ths upper grille ||5 and thence into the room, rather than going down through the longer heating passage. To cut out the abovedescribed delay switch IUI-|02, manual switch |09 bridges it so that the operator can make it ineective. Manual switch |09 is concealed, but

accessible through the removable upper grille expansion chamber 22 and the cabinet shell I y closed at the top by shutters 84 and having their bttoms c losed by base plate 6) form, in eiect, a plenum chamber in which the fans build up a slight pressure to produce the horizontally directed jet type of discharge stream. Note that this slight pressure aids in insuring discharge of thehigh temperature air throughout the length of long openings II 8 and |20.

As this substantially horizontally directed stream of high temperature air goes out from the heater cabinet, it is cooled in various Ways, including mixing with the room air and by hot air rising from the stream. Of course, this thin stream also fans out so that its lower portion will strike the door at a certain distance out from the heater cabinet. However, openings II8 and 20 are spaced just high enough above the iioor and the stream is directed substantially horizontally so that when this air does impinge against the floor it is at a suiciently low temperature to be non-objectionable and safe.

It will be apparent that the similarly mounted 'I'he base-chassis assembly carries all of the operating parts of'this heater independently of and unconnected to the. cabinet shell I. The only parts not carried by the chassis assembly are the fuel controls 5|, the shutter control handle 91 or SI5, and the conventional outside blower switch III). For repairs or service, it is not necessary to Work through doors, or the like; since the entire outer cabinet shell I can be readily lifted off the chassis. It will also be apparent thaty tliis'co'mplete chassis can be eiliciently assembledin a factory production line.

For removal of shell I, the fuel controls 5I are disconnected by screws 52a, the shutter handles 91 and 3|5 are disconnected from the shell as described in the foregoing specication, the wiring is suitably disconnected, and flue connection 39a is disconnected from the stack and is pulled out of opening 4I. 'I'hen the cabinet may be turned over and bolts I9 removed from the bottom to thus entirely disconnect the shell from the chassis assembly.

It will be noted that the entire blower unit and the entire shutter unit, and also the oil tank It is to be understood that the specific embodiments of the invention described herein are 'l to be taken as preferred examples of the same and that various modiiications and changes in the size, shape, arrangement, and uses of the Vseveral parts, features, and sub-combinations -ing passage having an open upper end and a lower opening, blower means associated with said passage to induce said downward flow, a grille across the open top of the cabinet, and a substantially horizontal openable closure unit extending across the upper end of said passage above said combustion unit andbelow said grille and comprising a series of interconnected pivoted shutter vanes which, when open, permit free upward rise of said thermal convection flow but occupy a small height.

2. A unit, forced-air circulation, space heater comprising an upright cabinet type housing having a relatively small depth from back to front and a substantially fiat back to go up against a room wall, liquid fuel burning heating means and means forming an associated contiguous air -heating passage in said housing, means deiining a separate upright narrow chamber in said housing to one side vof said heating means and passage, said chamber containing fuel supply float valve and control means, an upright fuel tank, and

blower means associated with said passage one' above the other in the order given.

3. A forced-air circulating, unit space heater comprising an upright, cabinet type housing having a relatively small depth from its front to its back, which is ilat to go up against a room wall, and having a limited height and a greater width from side to side, a liquid fuel burning heating unit and means forming an associated contiguous air heating passage extending across the depth and most of the width of said housing, a fuel supply tank and a blower unit mounted above said tank and operatively associated with said passage, said tank and said blower unit being mounted at one side of said housing, and partition means to separate the tank from said heating unit and passage.

4. A forced-air circulating, unit space heater comprising an upright, cabinet type housing having a relatively small depth from` its front to its back, which is iiat to go up against a room wall,

and having a limited height and a greater width from side to side, a liquid fuel burning heating unit and meansforming an associated contiguous air heating passage extending across the depth and most of the Width of said housing, a fuel supply tank and a blower unit mounted above said tank, said blower unit forcing air across said passage and heating unit and comprising a ,mounting holding two small parallel electric motors each having tandem propeller type fans, one

. at each motor end and with said fans at each end of the unit arranged adjacent, side by side, and extending from front to back of said cabinet type housing. said tank and said blower unit being mounted at one side of said housing, and partition means to separate the tank from said heating unit and passage.

5. A unit space heater comprising an upright, cabinet type housing having a front, back and sides, heating means therein, means forming an upwardly extending heating passage of appreciable width from side to side contiguous to and associated with said heating means, means closing the top part of said passage, a front discharge opening adjacent the bottom of said passage, and blower means in the upper part of said housing to one side of said passage, the blower discharge being directed across the width of said passage to give a long turbulent path` of forced downward reversed thermal air flow.

6. A unit space heater comprising an upright, cabinet type housing having a front, back and sides, an upright combustion heating unit in and extending across said housing and spaced therefrom to provide an air heating passage, means closing the top part of said passage, a discharge opening adjacent the bottom of said passage, blower means in the upper end side of the cabinet discharging across the width of said passage from side to side, and an air connning shroud extending about and spaced from said heating unit and spaced from said housing and having an air intake opening opposite said` blower discharge for entry of the blower stream.

'7. A cabinet, unit, air circulating space heater comprising a iloor supported, upright cabinet the depth of which from front to-back is considerabLv less than its width or its height, an upright partition in and extending'from front toback of said cabinet to separate it into two chambers, an upright liquid fuel burning combustion unit in one chamber and spaced from said partition and said cabinet side walls to form a passage for circulation of air to be heated, means forming a lower discharge opening from said passage, a liquid fuel tank in said other chamber carried by but insulatingly laterally spaced from said partition to permit an upward flow of cooling air against said tank, means forming a lower air inlet to said other chamber. said partition havig an opening communicating between the upper portions of said chambers and blower means to circulate air up through said nrst chamber and down through said other chamber and out its lower opening.

8. A cabinet, self-contained unit. air circulating space heater comprising a iloor supported, upright, rectangular cabinet having substantially ilat sides and top and having a narrow depth from front to back less than its width or height, an upright partition means secured to and extending from the front to the back walls of said cabinet to brace and stiifen it and to separate it into unequal width chambers, an upright oil burning combustion unit spaced from said partition means and the cabinet side walls in said larger chamber to provide an upwardly extending air heating passage, an upright oil tank in said smaller chamber mounted on and extending along said partition means but laterally spaced therefrom to provide an upwardly extending path for tank cooling air flow, and blower means in said smaller chamber discharging into and across the upper portion of said passage and mounted on the upper portion of said partition means.

9. A cabinet, self-contained unit, air circulating space heater comprising a floor supported,

space heater comprising'a frame pivotally carrying a row of interconnected, swingable shutters,

means to bias said shutters toward openposition, a member carried by and swingable with one of said shutters and having a portion to be engaged, a bimetallic spring strip mounted on said into unequal width chambers, an upright, oil l burning combustion unit spaced from said partition means and the cabinet side walls in said larger chamber to provide an upwardly extending air heating passage, an uprightoil tank in said smaller chamber mounted on and extending along said partition means but laterally spaced therefrom to provide an upwardly extending path for tank cooling air flow, and a blower unit in and extendingfrom front to back of said tank, said unit comprising a frame mounted on the upper part of said partition and carrying therein two small electric motors each having a fan on its motor shaft to blow air axially of said motors and fans across the upper portion of said passage and mounted on the upper portion of said partition means.

10. An air circulating, unit space heater comprising a base, an upright, liquid fuel burning, combustion unit mounted on said base, a contiguous air heating passage associated with said combustion unit, an upright partition means rigidly mounted on said base alongside of but spaced from said combustion unit, a fuel tank mounted on but spaced for insulation from the other side of said partition, an open bottom outer cabinet shell slidably ttingvdown over and removably secured to` saidbase and having means on its front and rear walls to removably and slidably secure them to the edges of said partition means to brace and stiffen said walls.

11. In an air heater of the type described having means forming an upwardly extending air heating passage and blower means operatively associated therewith to circulate air downwardly therethrough, means forming an air inlet for said blower means, an openable closure associated with the upper portion of said passage, and means responsive to an excessive temperature to automatically open said closure to permit upward ow of the heated air past said closure upon stopping of said blower during heating.

12. A unit space heater circulating heated air by natural, thermal circulation or by downward, blower-induced, reversed thermal ow and having means forming an upwardly extending air heating passage having a lower opening, blower means operatively associated with said passage, toinduce downward ow therethrough,'means forming an air inlet for said blower means, adjustable damper means at the upper end of said passage permitting said upward ow when open and preventing upward flow when closed for said downward ilow, means to bias said damper toward open position, and means to positively hold it in closed position, and to automatically release it upon stopping or failure of said blower means in normal heating operation to prevent overheating and to continue heating by gravity air circulation.

13. In an air circulating space heater of the type described, a top closure unit including a closure member movable from open to closedposition, means to bias it toward one position, and a single unitary means to both positively hold said member in the other position against said biasing means and to-automatically release it at a predetermined temperature.

14. A top closure unit for an air circulating frame and having means thereon to engage said portion to hold said shutters closed against said -biasing means andto release them at a predetermined temperature.

l5. A unit, air circulating space heater comprising a cabinet, a combustion unit and means forming a contiguous associated, upwardly-ex tending, air heating passage therein having an open upper end, a lower discharge for said passage, blower means in said cabinet located to the side of, but discharging into the upper portion of, said passage to force air downwardly therethrough, means closing the open upper end of said passage and means automatically opening said closing means upon non-operation of said blower means to permit the trapped, heated air to rise from said passage without passing through said blower means.

16. A unit space heater comprising a cabinet, a

combustion heating unit therein, means forming an upwardly extending air heating passage therein containing said heating unit, a lower discharge opening therefor, a blower discharging into and across the upper portion of said passage, means to close the upper portion of said passage for blower-forced discharge of heated air from its lower opening and to open it for upward discharge of unheated air for summer air circulation.

17. In combination, a room space heater having means forming an upwardly extending air heating passage having an upper and a lower opening, an associated, contiguous, high temperature, combustion, air-heating unit, means including a blower to circulate outside air downwardly through said passage to be heated and Vout its loweropening, means forming van inlet for unheated air to said blower, an openable closure closing said upper opening for said downward blower air circulation and, when open, permitting upward convection air circulation out through said upper opening, and meansto open said closure including a temperature responsive element positioned to be heated by said heating unit and close to and in the path of said blowers discharge to be swept by and cooled by air moved by said blower before this air has been heated suiiiciently to actuate said element to open said closure.

18. A cabinet-type unit space heater adapted to be supported on a room oor and circulating heated air by natural, upward, thermal convection or by downward, blower-induced, contrathermal flow, and comprising an upright opentopped cabinet having a front and back, an upright partition extending from front to back and dividing said cabinet into two upright passages opening through said open top, a liquid fuel tank mounted in one of said passages spaced from its side walls, means to provide cooling air flow past said tank, an upright combustion unit connected to said fuel tank, an upright heat shield wall spaced around said unit, said unit and said wall being enclosed in and laterally spaced from the walls of said other passage to provide upwardlyextending air-heating passageways in said other passage, said cabinet and said other passage having openings in their lower fronts discharging directly into the room, and operative or inoperative n.eans, including a blower in said cabinet, operative to circulate air downwardly through' said other heating passage and to force the high temperature heated air directly out into the room in a-stream directed across the room floor. said means, when inoperative, permitting said upward thermal flow out through said open top.

19. A cabinet-type unit space heater adapted to be supported on a room floor and circulating heated air by natural, upward, thermal convectionor by downward, blower-induced, contrathermal flow, and having an upright open-topped rectangular cabinet having a top and a substantially coextensive top opening and a wide front and being relatively narrow from front to back, an upright combustion drum, an upright heat shield wall spaced around said drum, said wall and said drum being inclosed in and laterally spaced from the walls of said cabinet to provide two upwardly-extending air-heating passageways, said cabinet having an opening in its lower front communicating with said two air-heating passageways and discharging directly into the room, and means, manually adjustable to operative .or inoperative condition and including a blower, to circulate air down through said two passageways and force it directly into the room in its operative condition, and to permit said upward thermal ilow out through said open top in its inoperative condition.

20. An air circulating space heater having a cabinet casing with a front and sides, a combustion heating unit in said casing, means forming, a contiguous, associated, air-heating passage extending downwardly, means forming a separate and communicating passage to one side of said combustion unit and having an air inlet, an adjacent iluid fuel supply tank for said heating unit, in said separate passage andspaced from it on all sides, and a blower drawing air through said separate passage past said fuel tank to cool it on all sides and then causing the same air to flow down through said air-heating passage.

21. An air circulating heater comprising an upright casing, a combustion heating unit therein, means for forcing outside airV into the upper portion of said casing and downwardly therethrough, and means permitting upward gravity air circulation through said casing responsive to a predetermined temperature rise therein upon stopping of said air forcing means to thus prevent excessive temperatures in said casing, said last means including, and operating in response to, a temperature responsive element positioned to be heated by said heating unit and to be cooled by said forced outside air.

22. An air circulating unit space heater comprising an upright casing, a combustion heating unit spaced therein to form an air-heating passageway, said casing having a lower opening and a large top opening at least substantially equal in area to the cross-sectional area. of said passageway to prevent restriction of the upward gravity air flow therethrough, means to force air into the upper portion ofl said passageway, downwardly therethrough, and out said lower opening, a movably mounted closure for said top opening, means biasing said closure to open position to permit operation by upward gravity circulation, latch means holding said closure in closed position against said biasing means to prevent upward circulation through said -top opening during said downward forced air circulation operation, said latch means including and being operated by a temperature responsive element, and

means to hold said closure in open or in closed positionl to permit operation by said upward gravity circulation or by said downward forced air circulation respectively.

23. An air circulating unit space heater comprising an upright, hoor-supported casing having a top, a combustion heating unit spaced therein to provide an upwardly extending airheating passageway, said casing havinga lower opening and an open top communicating with said passageway, means forming a lateral opening into the upper portion of said passageway below said open top, fan means forcing outside yair substantially horizontally through said lateral opening into the upper portion of said passageway below its upper opening, downwardly through said passageway and out its lower opening directly into the room to be heated, movable means having a closed position or an open position to close said open top to prevent major upward air ilow therethrough during said 'forced downward air circulation or to open said top to permit free upward gravity air circulation up past said lateral opening and up through said open top upon stopping of said fan means, and means to hold said movable means in open position.

24. An air circulating unitspace heater comprising an upright, floor-supported casing, a combustion heating unit spaced therein to provide an upwardly extending air-heating passageway, sai'd casing having a lower opening and an open top communicating with said passageway, means forming al lateral opening into the upper portion of said passageway below said open top. a fan in said casing forcing outside air substantially horizontally through said lateral opening against and around said heating unit'and into the upper portion of said passageway below its upper opening, downwardly through said passageway and out its lower opening directly into i the room to be heated, a closure for said open top movable `between closed and open positions. respectively, to prevent major upward air flow therethrough during said forced downward air circulation or to permit free upward gravity air circulation past said lateral opening and up through said open top upon stopping of said fan means. and means to hold said closure in open position.

25. In a space heater circulating heated air by natural, upward, thermal ilow or by blowerforced, downward, contra thermal ilow; means forming an upwardly extending air heating path having a lower opening communicating `directly with the room to be heated, blower means discharging into the upper parl; of, but located to one lside of, said. upwardly extending path so that it will not impede the upward ilow of hot air and be heated thereby, means to close o1 to open said path above the discharge of said blower means for said downward flow or said upward flow respectively, and means to hold said last means in open position.

26. In a room heating unit space heater circulating heated air by natural, upward, thermal flow or by blower-forced, downward, reversed thermal flow directly into the room and having heating means and associated means forming a contiguous, upwardly extending, air heating passage having a lower opening and an open top portion both opening directly into the room, openable means for closing o its open top portion for said blower-forced downward flow, means to operate said openable means, and

blower means discharging into the upper portion of said passage below said closingmeans but positioned laterally out of said upwardly extending passage to be out of the path of the upward flow.

27. An air heater unit selectively circulating heated air by natural, upward, thermal convection or by forced, downward, reversed thermal ow and having blower means, heating means, means forming an associated, contiguous, upwardly-extending air-heating passage having an upper opening, said blower means opening into said passage below its upper opening, and means to selectively and automatically open or to close only the upper opening of said passage for said upward ow or said downward ilow respectively.

28. An air heater unit circulating heated air by natural, upward, thermal convection or by downward, blower-induced, reversed thermal ow, having blower means to cause said downward flow and heating means, means forming anupwardly-extending air-heating passage contiguous to and associated with said heating means and blower and having a lower opening and its upper end having an opening substantially coextensive therewith, openable closure `heated air by natural, upward, thermal corivection or by downward, blower-induced, contra thermal flow, and having an 'upright air-heating y combustion unit, an upright cabinet enclosing and laterally spaced from said upright combustion unit to provide an upwardly-extending airheating passage, said cabinet having a top and a top opening substantially co-eXtensive with said top and having a lower opening discharging directly into the room, and operative or inoperative means, including a blower below said top and operatively communicating with said passage, operative to circulate heated air down'- means extending across said upper end opening,`

and means to operate said closure means.

29. A unit cabinet-type space heater having a cabinet 'housing, a combustion heating unit, means forming an upwardly-extending air-heating passage therein containing said heating unit, said passage having an opening through and substantially co-extensive with the top of said ing a relatively small depth from back to front.

and a substantially at back to go up against a room wall, liquid fuel burning heating means and means forming a contiguous, associated, air heating passage in said housing, and air circulating blower means associated with said passage, a fuel tank and fuel supply control valve means, all of said last three being within the housing, to the side thereor, alongside of the heating means and passage to achieve the small depth and the at back, said housing having an inlet opening and a low-level discharge opening communicating with said blower and said passage to provide a blower-induced, low-level discharge of heated air. v l

31. A unit space heater comprising an upright cabinet-type housing having a front, back, and sides. a combustion heating unit therein, means forming an upwardly-extending air-heating passage contiguous to and associated with said combustion unit and having a width from side wardly through said heating passage and to force it out said lower opening directly into the room, said. means, when inoperative, permitting said upward thermal convection ow out through said open top.

33. In combination, a heater, a blower, a movable blower-air-ow-controlling member, a latch holding said member in one position. means to bias said member toward another position, and a latch-controlling means including a temperature responsive element to be heated by said heater and to be positioned in and cooled by a relatively high velocity stream moved by said blower, whereby said latch-controlling means is operated in response to heat from said heater in the absence of said cooling high velocity air stream.

34. In combination, a heat exchanger, an associated blower, a movable air-ow-controlling closure member, and means to move said member including a temperature responsive element to be heated by said heat exchanger and positioned in and close to the blower discharge to be struck and cooled by the relatively high velocity stream moved by said blower while said closure member is in closed position.

35. In an air circulating heating device for heating a room and having a control element operative in response to temperature'changes, a combustion chamber heating said element, means includinga blower to circulate cooling air past said element to cool it during combustion and then in heat exchange relation with said combustion chamber to heat the air so that only during combustion said element is also operative in response to said air circulation due to the operation or non-operation of said blower.

36. The organization of claim 35 including an air ilow controlling means and in which said control element controls said air iiow controlling means. v

ROBERT B. EVANS. EUGENE F. FARRELL. 

